Field
A polymer electrolyte membrane for a fuel cell and a membrane-electrode assembly for a fuel cell including the same are disclosed.
Description of the Related Art
As interest in environment and energy depletion has increased, more research and development have been concentrated on commercialization of a fuel cell as an environmentally-friendly and renewable energy source. A polymer electrolyte membrane fuel cell (PEMFC) has been recognized as a promising system capable of replacing a conventional energy-transforming element due to high efficiency, high output density, a low operation temperature and environmentally-friendly characteristics.
However, there are various technical limits for more commercialization, the polymer electrolyte membrane fuel cell (PEMFC) needs to be improved in terms of high performance, cycle-life, low cost, and the like. Herein, a membrane-electrode assembly (MEA) shows improvement of a polymer electrolyte membrane fuel cell, and specifically, a polymer electrolyte membrane essentially is one of the essential factors having an influence on performance and cost of the membrane-electrode assembly (MEA).
The polymer electrolyte membrane for operating the polymer electrolyte membrane fuel cell (PEMFC) requires high proton conductivity, chemical stability, low fuel permeation, high mechanical strength, low moisture content, excellent dimensional stability, and the like, but a conventional polymer electrolyte membrane may not realize high performance in an environment of high temperature and low humidity. Accordingly, the conventional polymer electrolyte membrane tends to limit the use of the membrane-electrode assembly (MEA) and the polymer electrolyte fuel cell (PEMFC).
A fluorine-based polymer electrolyte membrane such as Nafion known to presently show the most excellent performance has the technological obstacle of complex manufacturing process, reduced efficiency according to permeation of a fuel, high cost, and the like, and a hydrocarbon-based polymer electrolyte membrane developed as its alternative also has a technological obstacle due to a problem of low proton conductivity under a high temperature/low humidity condition, mechanical durability under a repetitive wet/dry condition, and the like. Accordingly, research and development of the polymer electrolyte membrane as one of essential elements consisting of the membrane-electrode assembly having the most influence on commercialization of the polymer electrolyte fuel cell are desperately required.
Accordingly, development of a polymer electrolyte membrane having excellent durability, solving a problem occurring under a high temperature/low humidity condition, and contributing to increasing characteristics of the membrane-electrode assembly is required, and particularly, development of a hydrocarbon-based polymer electrolyte membrane having excellent dimensional stability is necessary to improve performance and cycle-life characteristics of the membrane-electrode assembly under various operation conditions.